Micro devices and micro-circuits have come into use in a wide variety of consumer, commercial, industrial, and military devices and equipment. Micro-circuits, such as integrated circuits, contain a large number of active circuit elements, such as transistors, and passive elements, such as resistors and capacitors, fabricated on a substrate.
Semiconductor integrated circuits consist of small monolithic dies made of a semiconducting material, such as silicon, having discrete areas into which impurities are diffused to form circuit elements, and having conductive paths between circuit elements on the chip formed by conductive lines formed using diffused impurities or patterned metal layers. In hybrid micro-circuits, circuit elements mounted on a ceramic substrate are usually interconnected by conductive ink paths on the substrate.
Functional portions of integrated circuits are typically in the form of very small, rectangular-shaped semiconductor dies. Electrical connections to integrated circuit dies are often made by wire bonding.
Many conventional semiconductor die (or “chip”) packages are of the type where a semiconductor die is molded into a package with a resin, such as an epoxy molding compound. The packages have leadfingers that project from the package body, to provide a path for signal transfer between the die and external devices. Other conventional package configurations have contact terminals or pads formed directly on the surface of the package.
Semiconductor package structures continue to advance toward miniaturization and thinning to increase the density of the components that are packaged therein while decreasing the sizes of the products that are made therefrom. This is in response to continually increasing demands on information and communication apparatus for ever-reduced sizes, thicknesses, and costs, along with ever-increasing performance.
These increasing requirements for miniaturization are particularly noteworthy, for example, in portable information and communication devices such as cellular phones, hands-free cellular phone headsets, personal data assistants (“PDA's”), camcorders, notebook personal computers, and so forth. All of these devices continue to be made smaller and thinner to improve their portability.
Conventional semiconductor packages are fabricated through the following processes: a die-bonding process (mounting the semiconductor die onto the paddle of a leadframe), a wire-bonding process (electrically connecting the semiconductor die on the paddle to inner leadfingers using bond wires), a molding process (encapsulating a predetermined portion of the assembly, containing the die, inner leadfingers and bond wires, with an epoxy resin to form a package body), and a singulation process (completing each assembly as individual, independent packages).
An exemplary semiconductor package, well known in the electronics industry, is the quad flat no-lead package (“QFN”). QFN packages typically comprise a leadframe, such as a conductive sheet stamped and etched, with a semiconductor die having a multitude of bond pads mounted to the top side of the leadframe. Wire bonds electrically connect the bond pads, of the semiconductor die, to a series of conductive leadfingers on the top side of the leadframe. Typically, the semiconductor die and the wire bonds are encapsulated within a molding compound.
In order to reduce manufacturing costs, the electronics industry is increasing the usage of QFN packages. In the manufacturing process, many obstacles must be overcome to deliver extremely small packages with increased number of input/output (I/O) in high volume. One such obstacle is being able to minimize the size of a leadless package in reference to a semiconductor die to be incorporated into the package.
Thus, a need still remains for leadframe package systems that can accommodate the largest possible semiconductor die without impacting the overall reliability of the package. In view of the ever-increasing commercial competitive pressures, it is increasingly critical that answers be found to these problems. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.